Means for retaining tool shanks in socket members



Sept 7, 1965 c. B. KREKELER MEANS FOR RETAINING TOOL SHANKS IN SOCKET MEMBERS Filed Aug. 14, 1961 INVENTOR. CLAUDE B. KEEKELER United States Patent 3,2i25,015 MEANS FOR RETAINING TOOL SHANKS IN SOQKET MEMBERS Claude B. Krekeler, Cincinnati, Ohio, assiguor to The Cincinnati Mine Machinery Co., Cincinnati, Ohio, a

corporation of ()hio Filed Aug. 14, 1961, Ser. No. 131,365 12 Claims. (Cl. 299-92) The invention relates to the problem of retaining the shanks of cutting tools in the shank-receiving perforations of socket members and of releasing the shanks therefrom, in simple and rapid operations. For convenience, the invention will be described with reference to mining machinery.

As is well known to one skilled in the art, the typical mine machine is provided with one or more sprocket driven cutter chains or trimming chains, the links of which embody socket members suitable for retaining the shanks of cutter bits or cutter bit holders. Mining operations require the frequent replacement of cutter bits, which are subject to excessive wear, abrasion and vibration. In the recent past the cutter bit shanks were held in the socket members by various arrangements of one or more set screws which were not only subject to loosening due to the excessive vibration, but made the task of bit replacement laborious, time-consuming and costly.

It is a primary object of the invention to provide means for holding tool shanks in socket members which is positive in action even when the bit is subjected to forces applied in the cutting direction, and which will not loosen when subjected to excessive vibration.

It is an object of the invention to provide means for of which exemplary embodiments will now be described.

Reference is made to the accompanying drawings wherein cluding the socket member, cutter bit and holding means of one embodiment of the present invention.

FIG. 2 is a partial sectional view of a cutter chain including the socket member, cutter bit and holding means of a second embodiment of the present invention.

FIG. 3 is a perspective view of the locking means of FIG. 2.

While the cutter chain does not constitute a limitation.

on the invention, FIG. 1 illustrates a typical cutter chain FIG. 1 is a partial sectional view of a cutter chain inwith a socket member 1 formed integrally with the chain one of the cheeks being shown at 2. In a chain of this type, the double link elements are interconnected by single link elements, partially indicated at 3 and 4. These single link elements are pivoted to the double link members by appropriate pintle means 5 and 6.

The socket element 1 has a perforation 7 to receive the shank 8 of a cutter bit 9. The term cutter bit, as used herein, is intended to embrace both a unitary structure consisting of a head and a shank, with a cutting point on the head, and also bit holder structures as known in the art comprising a head and a shank, and wherein the head is arranged to accept and retain renewable cutter bit elements. For purposes of an exemplary showing the cutter bit 9 is of the unitary structure type.

It has hitherto been suggested, see Patent No. 2,747,- 852, to provide a socket and bit shank structure in which element or link having two checks in spaced relationship, 5

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Patented Sept. 7," 1965 a pin extends transversely of the socket member perforation at the forward side, this pin entering a correspondingly shaped notch in the forward side of the shank. The engagement of the shank in the perforation involves a partial rotation or tilting of the bit; but the structure is one in which both downward and upward forces are positively resisted, and the bit may be made relatively cheaply since additional gauging abutments need not necessarily be provided. The structures of this case are an improvement upon those shown in the patent.

The socket member 1 of the present invention (see FIG. 1) is provided at one side of its perforation 7 with a transversely extending pivoting element or pin 10. This element is most conveniently provided by drilling an opening transversely of the socket member and inserting a hardened steel pin which is held against endwise movement by a press fit, by riveting, welding or in any suitable fashion. As illustrated, the pin 10 is so located that it is partially embedded in the socket element at the front or forward side of the perforation 7, i.e. in the portion marked 1a of the socket element. This portion may conveniently be made lower than the opposite portion and lateral wall portions of the socket member, as shown. The upper part of the interior wall of the portion 1a is sloped where it meets the pin 10 as shown at 11.

The rear portion (generally indicated at 1b) of the socket member has that part of its lower rear corner which lies between the checks of the double link relieved as at 12. A locking means 13 is pivoted to the socket member by means of a pivot pin 14. The pin 14 may be located in coaxial openings drilled transversely of the socket member and intersecting the space created by the relieved portion 12. The pin may be held against endwise displacement by any suitable means such as a forced fit, welding, etc;

One end 13a of the locking means 13 extends into the perforation 7. The other end 13b of the locking means 7 extends upwardly beyond the outside rear surface of the be mounted on the abutment 16 to extend within the coils of the spring'17 and hold it in place. The spring 17 urges 'T the end 1312 of the locking means 13 away from'the outside surface of the portion 1b of the socket member, j thereby maintaining the end 13a of the locking means within the perforation 7.

If the end 13b of the locking means is urged Itoward the socket member against the force of the spring 17,

the end 13a will be withdrawn from the perforation 7 as the locking means 13 pivots about the pin 14 in a clockwise direction (as seen in FIG. 1,). The end 13b of the locklng means may be otherwise configured for tool engagement, or as illustrated provided with a perforation 19 for the insertion of a tool to act as a lever to aid inurging the end 13 b toward the socket member, against the'force of the spnng 17 and any other factors tending to oppose movement of the locking means.

The shank 8 of the cutter bit or cutting element has its lower rear edge slanted inwardly and downwardly as at 20 and 21. The slanted portion 21 lies at a lesser angle to the axis of the shank than does the slanted portion 20.

The portion 13: of the locking means is turned .upwardly J as shown, and 1ts front edge may be relieved as at 22 so as to abut the surface 21 on the lower rear edge of the J:

provided with shank 8. The front edge of the shank 8 is a recess 23 to accept the pin 10.

In inserting the shank 8 of the bit into the socket memher, the 1n1t1al position of the shank is substantially that illustrated in FIG. 1 in dotted lines, the shank being inserted with a downward slantwise motion (as permitted by the beveled face 11 at the front side of the socket member opening) until the recess 23 of the shank can be engaged with the pivoting element 10. The locking means 13 may then be pivoted in a clockwise direction to bring its end 13a out of the perforation 7, and the cutter bit rocked about the pin to the position shown in solid lines in FIG. 1. When the locking means is released, its end will re-enter the perforation 7, and the abutment of its surface 22 against the surface 21 of the shank will prevent the cutter bit fromrocking forwardly about the pin 10. It will also be understood by one skilled in the art, that if the bit were placed in the position shown in dotted lines, the application of a sufficient force to the bit to rock it in the direction of the arrow A would cause the bit shank to depress the end 13a of the locking meansto permit the bit to seat as shown in solid linesin FIG. 1, after which the locking means would engage the surface 21. The application of such a force can be easily accomplished as by striking the bit with a hammer, maulor the like, or by means of a tool which, engaged with the bit, will provide a sufficiently extended lever arm to rock it into position against the resilient reaction of the locking means.

Once the bit is seated in the socket member, the pin 10 will prevent upward movement. While in use, the greatestforces acting upon the cutter bit are directed downwardly, and opposite the cutting direction.(i.e. from right to left in FIG. 1). Downward movement of the bit is prevented by the coaction of the pin 10 and the recess 23. However, if desiredan abutment surface 9a may be provided on the bit head to engage the top of the socket member. The forces exerted on the bit in a direction opposite the cutting direction are sustained by the interaction of the upper rear edge of the shank 8 and the rear face of the socket member perforation in the area designated at 24, and the interaction of the front edge of I the shank and the pin 10. Depending upon the fit of the parts there may be also be interengagement in the area 25.

The coaction of the end 13a of the locking means 13 and the surface 21 of the shank 8 insure that the bit-will not rock forwardly and be dislodged from the socket member even in the event of a force acting on the cutter bit 9 in the direction of the arrow B.

The removal of the cutter bit from the socket member is accomplished by causing the locking means 13 to pivot in a clockwise direction thereby removing the end 13a from the perforation 7 and from engagement'with the cutter bit shank 8. This is most easily accomplished by insertion of a tool (presenting a sufliciently extended lever arm) into the perforation 19 and applying force therewith in the direction of the arrow B. Once the end 13a has been removed from the perforation 7, the bit may be rocked forwardly about the pin 10. and withdrawn upwardly by hand.

A second embodiment of the present invention is illustrated in FIG. 2 wherein elements identical to those in FIG. 1 have been given like index numerals. This. second embodiment differs from that of FIG. 1 only with respect to the locking means. The lower part of the rear portion 1b of the socket member 1-contains a recess (generally indicated at 26) extending betweenthe cheeks of the double link and into the perforation 7. The recess 26 has an enlarged portion generally indicated at 2611. A locking means 27 is pivoted-in the recess 26'by means of the pin 28. The pin 28 is located in coaxial holes in the portion 16 of the socket member on either side of the recess 26. The pin may be held in place in the same manner as the pin '14 of FIG. 1.

The locking means is shown in FIG. 3. It is of generally rectangular cross-section, which cross-section may be reduced at the forward end as at 27a. This reduction of cross-section at the end 27a tends to prevent packing of cuttings and foreign material about that portion of the locking means which extends within the perforation 7.

The front end of the locking means is slanted as at 27b to allow abutment thereof against the slanted surface 21 of the shank 8 when the cutter bit is seated in the perforation 7. A hole 270 extends through the locking means transversely of its axis for receipt of the pivot pin 23.

The enlarged portion 26a of the recess 26 contains a block of resilient material 28, such as natural or synthetic rubber, chloroprene, or mixtures thereof. This resilient block serves to hold the locking means 27 in place, i.e. in the position shown in solid lines in FIG. 2. Italso serves to prevent packing of cuttings, etc. between the locking means and the portion 1b of the socket member 1.

In this embodiment, insertion of the cutter bit is much the same as shown in FIG. 1. If the locking means is pivoted in a clockwise direction (against the force of the resilient block 28) to the position shown in dotted lines, the reduced end 27a is depressed in the perforation 7, and the cutter bit may be rocked in place as described above. Rotation of the locking means may be accomplished by prying upwardly with a suitable tool that part of the locking means which extends outside the socket member or by engaging, the extending end with a socketed tooland lifting.

The bit may also be locked in place by applying a suitable force in the direction of the arrow A in the manner described'a'bove. Such a force will depress the end 27a ofthe locking means to permit the cutter bit to seat properly. Once in place, the locking means will prevent displacement ofthe bit when force is applied thereto in the direction of the arrow B. Other forces acting on the bit are counteracted in the same manner as described above. Removal of the bit may be accomplished by releasing the locking means, rocking the bit forwardly about the pin 10, and withdrawing the bit upwardly.

Modifications may be made in the structure of this invention without departing from the spirit of it. The invention having been described in certain exemplary embodiments, what is claimed as new and desired to be secured by Letters Patent is:

-1. ha socket member and cutter bit arrangement of the type comprising a socket member having an elongated, substantially rectangular socket forming perforation therein, a cutting member having an elongated, substantially rectangular shank, a fixedly secured pivoting element located in the perforation of said socket forming element intermediate the length thereof and projecting into said perforation, said pivoting element being engageable in a depression in the forward edge of said shank, said socket forming member being cut away forwardly above said pivoting element, and the rear lower portion of said shank being chamfered, whereby said shank can pivot forwardly in said socket member on said pivoting element and can be rocked rearwardly therein to a position in which the rear face of said shank above said chamfered portion can abut a rear face of said socket forming perforation to resist cutting strains imposed on the cutting member, the chamfered portion of said shank, when said shank is in its rearward position, lying in spaced relation to the rear face of said socket forming perforation to define a space therebetween, the improvement which comprises a recess in the lower rear portion of said socket member, and a releasable locking means pivotally mount-ed on said socket member'and movable in said recess whereby said locking means may be moved into a locking position wherein a portion of said locking means within said perforation can move upwardly to a position behind the chamfered portion of said shank, in which position it engages and holds said shank in its rearward position thereby preventing said cutting member from rocking forwardly on said pivoting element, and means accessible from the outside of said socket member for releasing said locking means by bringing said portion downwardly until it clears said shank.

2. The structure claimed in claim 1 wherein means are provided to urge said releasable locking means to its locking position, the pivotal mounting of said locking means being such that insertion of the bit shank in the perforation and the rocking of the bit shank to its final position will depress the said portion of the locking means and then allow the said portion to come into locking position behind the said shank.

3. The structure claimed in claim 1 wherein said chamfered portion of said shank comprises two adjacent downwardly and inwardly slanting surfaces, one above the other, on the lower rear edge of said shank, the lower of said slanting surfaces lying at a lesser angle to the axis of said shank than said other surface, the said portion of said locking means having a forward face with an angularity similar to the angular-ity of the lower one of said slanting surfaces, the said angular-ity being such that forces tending to move the lower end of said shank rear wardly will not displace said locking means.

4. The structure claimed in claim 3 wherein said recess is located in the lower rear edge of said socket member and wherein said locking means is generally L shaped with a portion pivoted in said recess, one end of said means extending outside said socket member, the other end, when said locking means is in locking position, extending upwardly within said space defined by said rear surface of said perforation and said chamfered portion of said shank, said last mentioned end having a slanted surface which abuts and'engages said lowermost slanted surface on said shank, thereby preventing said cutting member from rocking forwardly on said pivoting element.

'5. The structure claimed in claim 4 wherein said portion of said locking means which extends outside of said socket member is provided with a hole for receipt of a suitable tool to aid in moving said locking means.

6. The structure claimed in claim 4 wherein means are provided to urge said locking means toward the locking position.

7. The structure claimed in claim 4 wherein means are provided to urge said locking means toward the locking position, said means comprising an abutment means facing said socket member on said portion of said locking means which extends outside the socket member, a recess in said socket member opposite said abutment, a pin mounted on said abutment and extending part way into said recess, and a compression spring loosely mounted over said pin and extending from said abutment into said recess.

'8. The structure claimed in claim 3 wherein said recess extends through the lower rear portion of said socket member into said socket forming perforation and wherein said locking means comprises a bar of generally rectangular cross section pivoted within said recess, one end of said locking means extending outside of said socket member, the other end of said locking means, when said locking means is in locking position, extending within said socket forming perforation, said last mentioned end having a slanted surface which abuts and engages said lowermost slanted surface on said shank thereby preventing said cutting member from rocking forwardly on said pivoting element.

9. The structure claimed in claim 8 wherein the end of said locking means extending into said socket forming perforation is of reduced cross section.

10. The structure claimed in claim 8 wherein means are provided to urge said locking means to its locking position.

11. The structure claimed in claim 8 wherein said recess has an upward enlargement extending to the rear of the pivot point, and a body of resilient substance located in said enlargement and contacting said locking means to urge said means into locking position.

.12. -In a socket member and cutter bit arrangement of the type comprising a socket member having an elongated, substantially rectangular socket forming perforation therein, a cutting member having an elongated substantially rectangular shank, a fixedly secured pivoting element located in the perforation of said socket forming element intermediate the length thereof and projecting into said perforation, said pivoting element being engageable in a depression in the forward edge of said shank, said socket forming member being cut away forwardly above said pivoting element, and the rear lower portion of said shank being .chamfered, whereby said shank can pivot forwardly in said socket member on said pivoting element and can be rocked rearwardly therein to a position in which the rear face of said shank above said chamfered portion can abut a rear face of said socket forming perforation to resist cutting strains imposed on the cutting member, the chamfered portion of said shank, when said shank is in its rearward position, lying in spaced relation to the rear face of said socket forming perforation to define a space therebetween, the improvement which comprises releasable locking means pivoted with respect to said socket member, having a portion extending into the said perforation and having an up and down movement therein, so located that the said end of the releasable locking means can be depressed by the end of the shank of the ,cutter bit as the cutter bit is swung into final cutting position, whereupon the end of said releasable locking means can move upwardly in said perforation engaging behind the chamfered portion of the shank of the cutter bit to inhibit tilting of the cutter bit out of cutting position, and means for resiliently biasing said locking means into locking position.

References Cited by the Examiner UNITED STATES PATENTS 1,375,638 4/21 Kienzle. 2,747,852. 5/56 Krekeler.

BENJAMIN HERSH, Primary Examiner. 

1. IN A SOCKET MEMBER AND CUTTER BIT ARRANGEMENT OF THE TYPE COMPRISING A SOCKET MEMBER HAVING AN ELONGATED, SUBSTANTIALLY RECTANGULAR SOCKET FORMING PERFORATION THEREIN, A CUTTING MEMBER HAVING AN ELONGATED, SUBSTANTIALLY RECTANGULAR SHANK, A FIXEDLY SECURED PIVOTING ELEMENT LOCATED IN THE PERFORATION OF SID SOCKET FORMING ELEMENT INTERMEDIATE THE LENGTH THEREOF AND PROJECTING INTO SAID PERFORATION, SAID PIVOTING ELEMENT BEING ENGAGEABLE IN A DEPRESSION IN THE FORWARD EDGE OF SAID SHANK, SAID SOCKET FORMING MEMBER BEING CUT AWAY FORWARDLY ABOVE SAID PIVOTING ELEMENT, AND THE REAR LOWER PORTION OF SAID SHANK BEING CHAMFERED, WHEREBY SAID SHANK CAN PIVOT FORWARDLY IN SAID SOCKET MEMBER ON SAID PIVOTING ELEMENT AND CAN BE ROCKED REARWARDLY THEREIN TO A POSITION IN WHICH THE REAR FACE OF SAID SHANK ABOVE SAID CHAMFERED PORTION CAN ABUT A REAR FACE OF SAID SOCKET FORMING PERFORATION TO RESIST CUTTING STRAINS IMPOSED ON THE CUTTING MEMBER, THE CHAMFERED PORTION OF SAID SHANK, WHEN SAID SHANK IS IN ITS REARWARD POSITION, LYING IN SPACED RELATION TO THE REAR FACE OF SAID SOCKET FORMING PERFORATION TO DEFINE A SPACE THEREBETWEEN, THE IMPROVEMENT WHICH COMPRISES A RECESS IN THE LOWER REAR PORTION OF SAID SOCKET MEMBER, AND A RELEASABLE LOCKING MEANS PIVOTALLY MOUNTED ON SAID SOCKET MEMBER AND MOVABLE IN SAID RECESS WHEREBY SAID LOCKING MEANS MAY BE MOVED INTO A LOCKING POSITION WHEREIN A PORTION OF SAID LOCKING MEANS WITHIN SAID PERFORATION CAN MOVE UPWARDLY TO A POSITION BEHIND THE CHAMFERED PORTION OF SAID SHANK, IN WHICH POSITION IT ENGAGES AND HOLDS SAID SHANK IN ITS REARWARD POSITION THEREBY PREVENTING SAID CUTTING MEMBER FROM ROCKING FORWARDLY ON SAID PIVOTING ELEMENT, AND MEANS ACCESSIBLE FROM THE OUTSIDE SAID SOCKET MEMBER FOR RELEASING SAID LOCKING MEANS BY BRINGING SAID PORTION DOWNWARDLY UNTIL IT CLEARS SAID SHANK. 